Today I discovered something I actually haven't seen before - the cross-browser support in ASP.NET. More specifically with the Label and Calendar controls.
When I decided to check out my project in Opera to make sure it rendered fine there, I discovered that the properties like Font-Size, ForeColor and similar are rendered inside a style attribute as CSS, but in Opera the controls are rendered using properties to control the look. I really don't see the logic in Opera being marked as a down-level browser when it in fact is more up-level than IE6.
I have yet to find a way to override this behavior, so it seems the only way to work around this is to change the styles on label controls using the CssClass property and thus refering to a CSS element.
Hopefully this will be fixed in the next version of ASP.NET - a way to disable this browser-check stuff would be really neat!